Information
-
Patent Grant
-
6506033
-
Patent Number
6,506,033
-
Date Filed
Thursday, May 31, 200123 years ago
-
Date Issued
Tuesday, January 14, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Freay; Charles G.
- Belena; John F
Agents
-
CPC
-
US Classifications
Field of Search
US
- 417 93
- 417 96
- 417 97
- 417 98
- 417 4131
- 417 420
- 417 470
- 417 269
- 417 415
- 074 57
- 092 71
-
International Classifications
-
Abstract
A miniature pump equipped with: a pump chamber communicated with a suction port by way of a check valve and communicated with a discharge port by way of another check valve; a driving portion for performing a pump function by increasing and decreasing a volume of the above described pump chamber; a driving plate attached to the above described driving portion for reciprocating the driving portion; a rotating plate fixed to an output shaft of a motor; a ball disposed at a location which is between the above described driving member and the above described rotating plate, and apart from the above described output shaft; and means for applying a force to a surface of the above described driving plate on a side of the above described rotating plate for bringing the above described driving plate into close contact with the above described ball, in which an inclined direction of the above described driving plate is continuously changed by a movement caused due to rotations and revolutions of the above described ball as the above described rotating plate rotates, thereby reciprocating the above described driving portion and performing a pump function.
Description
BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates to a miniature pump.
b) Description of the Prior Art
Out of conventional miniature pumps, a pump disclosed by Japanese Patent Kokai Publication No. Sho 62-291484 is known as a miniature pump which uses a diaphragm and has a configuration schematically shown in FIG.
1
.
This conventional miniature pump uses a disk like driving plate
5
fitted over a driving shaft
4
which is fitted into a crank stand
3
fixed to an output shaft
2
of a motor
1
as shown in FIG.
1
. Disposed around an outer circumferential portion of this disk like driving plate is a singularity or a plurality of cup diaphragm members
6
which have upward openings. In case of a pump in which the plurality of diaphragm members
6
are disposed, the diaphragm members are arranged at equal intervals on a circumference. Furthermore, a reference numeral
7
represents a cylindrical valve, a reference numeral
8
designates another valve, a reference numeral
9
denotes a suction port and a reference numeral
10
represents a discharge port.
The a miniature pump drives the motor
1
to rotate its output shaft
2
, which rotates the crank stand
3
and causes a dish-turning-gyrating movement of the driving plate
5
by way of the driving shaft
4
, thereby moving up and down driving portions
6
a
at roots of the diagram members
6
. Accordingly, the root portion (driving portion)
6
a
of the cup like diaphragm member
6
which is located to a left side, for example, in
FIG. 1
moves to go up from a lowered condition and the root portion (driving portion)
6
a
of the diaphragm member
6
which is located on a right side moves to go down from a raised condition.
By the up-down movements of the root portions of the diaphragm members
6
, the diaphragm members allow a fluid to be sucked and discharged at intervals of a definite time, thereby performing a pump function.
In order to ideally reciprocate the diaphragm members
6
, the above described conventional miniature pump must be configured so as to align a center G of the diaphragms
6
of the driving plate
5
with a fixed center of the output shaft. That is, the center G must be located on a prolonged line of the output shaft
2
. For this reason, the driving shaft requires a bearing and the driving plate
5
is prolonged, thereby enlarging the pump as a whole.
Furthermore, since the driving portion of the diaphragm member performs a reciprocal movement per rotation of the output shaft
2
, the diaphragm member
6
is abnormally deformed and a service life of the diaphragm member is extremely shortened when a rotational frequency of the motor is enhanced, that is, when the output shaft is rotated at a higher speed. A motor which is large and has strong power is therefore required.
Another conventional miniature pump is a centrifugal pump (impeller pump). This conventional centrifugal pump has a configuration, for example, shown in FIG.
2
. In
FIG. 2
, a reference numeral
21
represents a pump chamber side case, a reference numeral
22
designates a driving side case, a reference numeral
23
denotes a partition wall for partitioning a pump chamber
24
from a driving section
25
, a reference numeral
26
represents an O ring, a reference numeral
27
designates an output shaft of a motor
28
, a reference numeral
29
denotes a driving side yoke plate, a reference numeral
30
represents a driving side magnet fixed to the yoke plate
29
, a reference numeral
31
designates a spherical bearing, a reference numeral
32
denotes a holding section for a pump chamber side magnet and the like, a reference numeral
33
represents a pump chamber side magnet, a reference numeral
33
a
designates a pump chamber side yoke plate, a reference numeral
34
denotes a cover body, a reference numeral
35
represents an impeller, a reference numeral
39
designates a fluid inlet port and a reference numeral
40
denotes a fluid outlet port.
This centrifugal pump (impeller pump) drives the motor
28
to rotate the output shaft
27
, which rotates the driving side magnet
30
so that the pump chamber side magnet
33
is rotated by magnetic coupling and the impeller
35
is rotated together with the pump chamber side magnet, thereby performing a pump function.
This conventional pump is used as a pump for supplying a liquid, but has defects that the pump cannot enhance a pressure or must be configured large for obtaining a high pressure and that the pump has a low efficiency. Furthermore, the pump has defects that it has a weak force to such a liquid, whereby the pump requires priming water or must be installed lower than a level of a liquid to be sucked at a start time.
Furthermore, a pump which has a configuration shown in
FIG. 3
is known as a conventional example of diaphragm pump out of miniature pumps.
In
FIG. 3
, a reference numeral
41
represents a motor, a reference numeral
42
designates a speed reduction mechanism which consists of a gear
43
attached to an output shaft
41
a
of the motor
41
and a gear
44
in mesh with the gear
43
, a reference numeral
45
denotes a driving shaft which is fitted and fixed into and to the gear
44
so as to be eccentric from a shaft
44
a
of the gear
44
, a reference numeral
46
represents a connecting rod which is rotatably coupled with the driving shaft
45
, and a reference numeral
47
a diaphragm which is fixed to a tip of the connecting rod
46
and made of synthetic rubber or the like. This diaphragm
47
has a sealing member
47
a
which is disposed on its outer circumferential portion and is sandwiched between a clamp plate
48
and a casing
49
, thereby sealing a pump chamber
50
from external air. Furthermore, a reference numeral
51
represents a suction port, a reference numeral
52
designates a discharge port, and check valves
53
and
54
such as leaf valves are disposed in the suction port
51
and the discharge port
52
respectively.
When the motor
41
is driven to rotate the output shaft
41
a
of the motor
41
in the diaphragm pump which has the above described configuration, the gear
44
of the speed reduction mechanism
42
is rotated and the driving shaft
45
moves the diaphragm
47
up and down by way of the connecting rod
46
, whereby a volume of the pump chamber
50
is increased and decreased by the up and down movements of the diaphragm
47
. The leaf valve
53
is opened and a fluid is sucked through the suction port
51
when the volume of the pump chamber
50
is increased, and the leaf valve
54
is opened and the fluid is discharged through the discharge port
52
when the volume of the pump chamber
50
is decreased, whereby the diaphragm pump performs a pump function.
Since the pump shown in
FIG. 3
requires a speed reduction mechanism and a crank mechanism, the pump is complicated in a structure of a driving section for performing the pump function and is large. Furthermore, the pump produces remarkable noise during operation.
Furthermore, there is known a pump which is invented by the inventor of this invention and disclosed by Japanese Patent Kokai Publication No. Hei 11-230046. This miniature pump has a configuration shown in FIG.
4
.
In
FIG. 4
, a reference numeral
71
represents a motor, a reference numeral
72
designates an output shaft of the motor
71
, a reference numeral
73
denotes a disk like rotating plate which is fixed to the output shaft
72
and has a groove
73
a
having an arc like sectional shape and formed along a circumference around the output shaft
72
as a center. A reference numeral
75
represents a driving plate substantially like a disk, for example, and has, like the rotating plate
73
, a groove
75
a
which has an arc like sectional shape and formed along a circumference around a center of the driving plate
75
. A ball
74
is disposed between the groove
73
a
of the rotating plate
73
and the groove
75
a
of the driving plate
75
which are formed in opposition to each other. A reference numeral
76
represents a cylinder, a reference numeral
77
designates a diaphragm which has a driving portion
77
b
fixed to the driving plate
75
and a reference numeral
78
denotes a valve housing (cover body): a pump chamber
82
being formed by sandwiching the diaphragm
77
between the valve housing
78
and the cylinder
76
, and tightening and fixing the diaphragm
77
to the cylinder portion
76
with a screw
83
, thereby sealing the diaphragm
77
. Though
FIG. 4
shows only one pump chamber
82
which is formed in a diaphragm portion
77
c
of the diaphragm, two or more diaphragm portions
77
c
(pump chamber
82
) may be formed to compose a multi-cylinder pump.
Formed integrally with the valve housing
78
are a valve chamber
79
and a discharge port
80
communicated with the valve chamber
79
, and a valve
77
a
which is formed integrally with the diaphragm
77
is disposed in the valve chamber
79
. Furthermore, a reference numeral
84
represents a check valve and a reference numeral
85
designates a suction port.
The pump which is described above is set so that the rotation plate
73
and the driving plate
75
are raised until a center of a top surface is brought into contact with a stopper pin
76
a
disposed at a center of the cylinder
76
and the driving plate
75
is inclined. A stroke for a reciprocal movement of the driving portion
77
b
formed integrally with the diaphragm
77
is determined by an inclination angle of the driving plate
75
and the like. Furthermore, a reference numeral
90
represents a bias spring which produces appropriate friction by loading the ball when a load on the ball is light. Therefore, this bias spring
90
may not be used when appropriate friction is applied to the ball
74
in a relation to a load.
When the output shaft
72
is driven and rotated by the motor
71
in this miniature motor, the rotating plate
73
fixed to the output shaft
72
is rotated. When the rotating plate
73
is rotated, the ball
74
which is pressed to the rotating plate
75
by the bias spring
90
and the like moves around the output shaft
72
in a direction identical to a rotating direction of the rotating plate
73
while rotating. Since the groove
73
a
of the rotating plate
73
and the groove
75
a
of the driving plate
75
which have the arc like sectional shapes have radii nearly equal to each other (the radius of the groove
75
a
of the driving plate
75
is generally a little shorter), the ball
74
moves at a speed about half a speed of the rotating plate
73
, whereby the ball
74
makes nearly one turn around the output shaft
72
when the rotating plate
73
makes two turns.
Accordingly, the ball
74
makes half a turn and moves from a location on a right side of the output shaft
72
to a location on a left side of the output shaft
72
when the rotating plate
73
makes one turn from a position shown in
FIG. 4
, whereby the driving plate moves the driving portion
77
b
of the diaphragm
77
from an upper position to a lower position. The rotation of the rotating plate
73
causes upward and downward movements of the driving portion
77
b
as described above, thereby performing a pump function. That is, the downward movement of the driving portion
77
b
from the location shown in
FIG. 4
increases a volume of the pump chamber
82
and opens the valve
84
, thereby allowing a fluid to flow into the pump. When the driving portion
77
b
goes up again, the volume of the pump chamber
82
is decreased and a gas is pressurized in the pump chamber, thereby opening the valve
77
a
and allows the fluid to be discharged from the discharge port
80
through the valve chamber
79
.
While repeating the movements described above, the pump performs the pump function by sucking the fluid from the suction port
85
and discharging the fluid from the discharge port
80
.
When the bias spring is not used, this conventional miniature pump allows the driving plate
75
to float up during driving, thereby being incapable of sufficiently transmitting the rotation of the rotating plate
73
by way of the ball
74
, reciprocating the diaphragm portion at an accurate speed or at accurate time intervals, and supplying and sucking the fluid stably. Furthermore, the conventional miniature pump may produce noise since the driving plate
85
and the ball
74
are repeatedly brought into contact and separated.
In order to correct this defect, it is conceivable to dispose the bias spring
90
as shown in the conventional example as shown in
FIG. 4
, thereby keeping the driving plate
75
in contact with the ball
74
.
When the bias spring
90
has a weak force, this method is ineffective and allows the pump to remain unchanged from the pump in which a bias spring is not used. Furthermore, the driving plate is inclined remarkably when the bias spring
90
has a strong force. A reason is that a side of the driving plate
75
to which the force of the bias spring
90
is exerted (a left side in
FIG. 4
) is pushed down using the ball
74
as a fulcrum as shown in
FIG. 4 and a
left side of the driving plate
75
in
FIG. 4
is lowered, thereby enlarging an inclination angle. As a result, the driving plate
75
is apart from a tip of the stopper pin
76
a
, whereby a variation in inclination of the driving plate
75
is unstable, and the upward and downward movements (reciprocal movements) of the diaphragm
77
is unstable. When the bias spring
90
has a force which is further too strong, the inclination angle is further enlarged and the driving plate
75
comes into contact with the rotating plate
73
, thereby posing problem that the rotation of the rotating plate
73
is unstable, that noise if further produced and the like.
The pump mentioned as the conventional example shown in
FIG. 4
poses the problem when a spring has a weak force or when the spring has a strong force reversely, allows a spring force to be set appropriately only within a narrow width and operates favorably only within an extremely a narrow range of spring forces. Accordingly, the pump requires extremely high precisions for parts such as the bias spring
90
, the rotating plate
73
, the ball
74
and the driving plate
75
, thereby requiring a high manufacturing cost.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a miniature pump characterized in that the pump comprises: a pump chamber which is communicated with a suction port by way of a check valve and communicated with a discharge port by way of another check valve; a driving portion which performs a pump function by increasing and decreasing a volume of this pump chamber; a driving portion which performs the a driving portion is attached and which reciprocates the driving portion, a ball which is disposed at a location between the rotating plate and the driving plate, and apart from a rotating shaft of the rotating plate; and a spring which brings the driving plate into pressure contact with the ball by applying a force from a side of the rotating plate, an inclined direction of the driving plate is continuously changed by a movement of the ball caused due to rotation and revolution of the ball, and a pump function is performed by reciprocating the driving portion due to the change of the inclined direction of the driving plate.
Another object of the present invention is to provide a miniature pump comprising: a pump chamber which is communicated with a suction port by way of a check valve and communicated with a discharge port by way of another check valve; a driving portion which increases and decreases a volume of the pump chamber; a driving plate which reciprocates the driving portion; a rotating plate which is fixed to an output shaft of a motor; a ball which is disposed between the rotating plate and the driving plate; and a cam surface which is disposed on a rotating plate side of the driving plate, wherein the ball moves while rotating and revolving due to rotations of the rotating plate, and wherein rotations of the rotating plate causes rotations and revolution of the ball which move the ball, the movement of the ball produces a function of the cam surface which reciprocates the driving portion together with the driving plate, thereby performing a pump function.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 through 4
are diagrams showing configuration of prior art conventional miniature pumps;
FIG. 5
is a diagram showing a configuration of a first embodiment of the miniature pump according to the present invention;
FIG. 6
is a diagram showing a configuration of a second embodiment of the miniature pump according to the present invention;
FIG. 7
is a diagram showing a form of a diaphragm to be used in the first and second embodiments;
FIG. 8
is a diagram showing a configuration of a third embodiment of the miniature pump according to the present invention;
FIG. 9
is a diagram showing a condition where a ball has traveled 180° in the miniature pump shown in
FIG. 8
;
FIG. 10
is a diagram showing a relation between rotations of a rotating plate and a movement of a driving portion;
FIG. 11
is a diagram showing a configuration of a fourth embodiment of the miniature pump according to the present invention;
FIG. 12
is a diagram showing a configuration of a fifth embodiment of the miniature pump according to the present invention; and
FIG. 13
is a plan view of a case of the pump shown in FIG.
12
.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 5
is a diagram showing a first embodiment of the present invention, wherein a reference numeral
101
represents a driving motor, a reference numeral
102
designates an output shaft of the motor
101
, a reference numeral
103
denotes a disk like rotating plate which is fixed to the output shaft
102
of the motor
101
, a reference numeral
104
represents a ball disposed in a concave groove
103
a
which is formed in the rotating plate
103
along a circumference around the output shaft
102
of the motor and a reference numeral
105
designates a driving plate which has a concave groove
105
a
formed along a circumference at a location of a bottom surface corresponding to the concave groove
103
a
of the rotating plate
103
and a supporting shaft
105
b
at a center: the ball
104
being disposed between the concave groove
103
a
of the rotating plate
103
and the concave groove
105
a
of the driving plate
105
. Furthermore, a reference numeral
106
represents a cylinder, a reference numeral
107
designates a diaphragm and a reference numeral
116
denotes a retainer: the diaphragm
107
being interposed between the driving plate
105
and the retainer
116
and fixed to the driving plate
105
with a screw
116
a
, and portions such as the retainer
116
and the screw
116
a
having a function like that of a piston. Disposed at a center portion of the cylinder
106
is a supporting bearing
106
b
which bears a supporting shaft
105
b
disposed on the driving plate
105
. Furthermore, a reference numeral
108
represents a cover body, a reference numeral
109
designates a valve chamber, a reference numeral
110
denotes a discharge port, a reference numeral
111
represent a case, a reference numeral
112
designates a pump chamber, a reference numeral
114
denotes a suction valve and a reference numeral
115
represents a suction port. Though two pump chambers are shown in
FIG. 5
, three or more pump chambers of only one pump chamber may be used in the first embodiment. In addition, a reference numeral
107
a
represents a discharge valve which is formed integrally with the diaphragm
107
and a reference numeral
109
designates a valve chamber.
In a pump according to the first embodiment, a spring
117
is disposed between the supporting shaft
105
b
of the driving plate
105
and the rotating plate
103
located on an opposite side. In order to prevent this spring
117
from being influenced by rotations of the rotating plate
103
, the pump according to the first embodiment is configured to use a spring bearing
119
which is attached to the output shaft
102
by way of a ball bearing
118
so that the spring
117
is located between the spring bearing
119
and the driving plate
105
.
The reciprocating pump according to the first embodiment rotates the output shaft
102
by driving the driving motor
101
, thereby rotating the rotating plate
103
. When the rotating plate
103
is rotated, the ball
104
moves along the concave grooves
103
a
and
105
a
around the output shaft
102
. When the ball
104
moves, an inclined direction of the driving plate
105
is changed consecutively and continuously. In a condition shown in
FIG. 5
, for example, the ball
104
is located on a most right side and the driving plate
105
is inclined, whereby the driving plate
105
is inclined so that a right side is highest and a left side is lowest. Due to this inclination of the driving plate
105
, the retainer
116
which performs the piston function is pushed in the right side pump chamber to decrease a volume of the pump chamber
112
whereas the retainer
116
which performs the piston function is pushed down in the left side pump chamber to increase a volume of the pump chamber
112
.
When the ball
104
successively moves along the grooves
103
a
and
105
a
until the ball is located on the left side, the driving plate
105
is inclined in a reverse direction, whereby the retainer
116
having the piston function is lowered in the right side pump chamber
112
to increase the volume, whereas the retainer
116
having the piston function is raised in the left side pump chamber to decrease the volume.
The inclination of the driving plate
105
is changed 360° continuously around a fulcrum (supporting shaft) and the pump function is performed continuously by repeating this change.
The reciprocating pump according to the first embodiment is configured to use the spring
117
disposed between the driving plate
105
and the spring bearing
119
so that the spring
117
pushes up the driving plate
105
in the vicinity of the supporting shaft
105
b
formed at the center of the driving plate
105
. Owing to a raising force of the spring
117
which pushes up the driving plate
105
in the vicinity of the driving plate
105
, exerted to a contact portion between the ball
104
and the groove
105
a
is a force which pushes down the ball while the supporting shaft
105
b
is depressed to the supporting shaft bearing
106
b
. That is, an upward force of the spring
117
in the vicinity of the supporting shaft
105
b
functions to bring the supporting shaft
105
b
into close contact with the supporting shaft bearing
106
b
, and since the ball
104
inclines the driving plate
105
(the driving plate is higher on a side of the ball
104
), the spring is set in a condition where the spring is elongated on a side B of the ball as shown in
FIG. 5
, whereby un upward force of the spring on a side A opposite to the ball
104
is stronger than an upward force of the spring on the side B of the ball
104
, thereby exerting a force of the driving plate
105
which presses the ball
104
. Accordingly, the spring
117
functions to return the inclined driving plate
105
to a horizontal position.
The reciprocating pump according to the first embodiment of the present invention utilizes the force of the spring
117
to return the inclination of the driving plate
105
caused by the ball
104
, thereby keeping the driving plate
105
always in contact with the ball
104
. As a result, the reciprocating pump changes an inclined direction of the driving plate
105
continuously at a constant speed and allows the rotations of the rotating plate
103
to cause a secure movement of the ball
104
without slipping, thereby being capable of performing a pump function continuously while producing constant phase difference (time difference) between the pump chambers.
Furthermore, since the force which is applied from the spring
117
to the driving plate functions to reduce an inclination angle of the driving plate, the miniature pump according to the first embodiment is free from a fear that even a portion (portion which is brought closest to the rotating plate
103
) of the driving plate
105
may be brought into contact with the rotating plate
103
, thereby being capable of favorably driving the driving plate
105
and performing a favorable pump function. Since the force of the spring
117
is sufficient so far as the force is not weaker than a certain definite level, the spring poses no problem even when the force of the spring is more or less weakened or even when the spring is used for a long time.
FIG. 6
is a diagram showing a reciprocating pump according to a second embodiment of the present invention.
In
FIG. 6
, a reference numeral
101
represents a driving motor, a reference numeral
102
designates an output shaft of the motor
101
, a reference numeral
103
denotes a rotating plate which has a concave groove
103
a
, a reference numeral
104
represents a ball, a reference numeral
105
designates a driving plate which has a concave groove
105
a
, a reference numeral
106
denotes a cylinder, a reference numeral
107
represents a diaphragm, a reference numeral
110
designates a discharge port, a reference numeral
111
denotes a case, a reference numeral
112
represents a pump chamber, a reference numeral
114
designates a suction valve, a reference numeral
115
denotes a suction port and a reference numeral
116
represents a retainer; these members being substantially the same as those of the first embodiment shown in FIG.
5
.
A reference numeral
117
represents a spring which is disposed between the case and the driving plate
105
so as to be located outside the rotating plate
103
utilizing a space at a lower end of the case.
The pump according to the second embodiment is different in a location of the spring
117
from the pump according to the first embodiment as described above.
The reciprocating pump according to the second embodiment drives the driving motor
101
to rotate the output shaft
102
, thereby rotating the rotating plate
103
. When the rotating plate
103
is rotated, the ball
104
which is disposed between the rotating plate
103
and the driving plate
105
moves along the concave grooves
103
a
and
105
a
while rotating, and when the movement of the ball
104
causes a consecutive and continuous change of an inclined direction of the driving plate
105
. Accordingly, a retainer
116
which is attached to the driving plate
105
and functions like a piston moves up and down (reciprocates), thereby performing a pump function.
The pump according to the second embodiment performs the pump function which is similar to that of the pump according to the first embodiment.
Different from the first embodiment, however, the second embodiment uses the spring
117
which is disposed in an internal space of the case which is under a circumferential portion of the driving plate
105
and outside the rotating plate
103
.
Since the second embodiment is configured to dispose the spring in the space of a circumferential portion of the case as described above, the second embodiment facilitates to dispose the spring and does not require configuring the spring so as to have a portion having a special structure unlike the first embodiment, that is, disposing the spring which is attached to the output shaft
102
by way of the ball bearing
118
, thereby simplifying a configuration of the pump and providing a merit from a view point of a cost.
Furthermore, the spring which is disposed under a circumferential portion of the driving plate is capable of maintaining a condition where the ball
104
is secure contact with the driving plate
105
even when the spring has a relatively weak force.
In the second embodiment, a raising force of a left side spring which pushes up the circumferential portion of the driving plate
105
functions to push up a supporting shaft
105
b
at the center portion of the driving plate
105
and to be brought into close contact with a supporting bearing
106
b
and to bring the driving plate
105
into close contact with the ball
104
using the supporting shaft
105
b
as a fulcrum. Since a distance as measured from the left side spring to the supporting shaft functioning as the fulcrum is long, a weak force of the spring functions as a strong force of the driving plate which presses the ball
104
. Specifically, the ball
104
is moved securely by a force of the driving plate
105
pushing the ball
104
which is produced as a difference between a pushing down force exerted to the ball
104
by pushing up the driving plate
105
with a compressed spring (the left side spring in
FIG. 6
) and a force of a relatively elongated spring (a right side spring in
FIG. 6
) pushing up the driving plate
105
.
Furthermore, the first and second embodiments are characterized in that configurations of diaphragms and the like which compose the pump chamber are different from those of the conventional reciprocating pump shown in FIG.
4
.
That is, a pump chamber according to each of these embodiments has a shape of a nearly truncated cone (a sectional shape of a nearly trapezoid) and is retained at a circumferential portion of the driving plate
105
with the retainer
116
, and a diaphragm
107
is attached to the driving plate
105
by fixing the retainer
116
to the driving plate
105
with a screw
116
a.
This diaphragm is configured as shown in FIG.
7
and fixed by sandwiching the diaphragm between a cylinder
106
and a cover body
108
as shown in
FIG. 5
or FIG.
6
. Furthermore, the diaphragm is fixed by screwing the retainer
116
to the driving plate as described above.
FIG. 7
shows the diaphragm in a condition where the diaphragm is rotated 90° from a position shown in
FIG. 5
or FIG.
6
.
A portion C and a portion D of this diaphragm shown in
FIG. 7
have linear sectional shapes, the portion C being inclined steeply and the portion D being inclined gently.
Since the diaphragm has a linear sectional shape as described above which changes little as shown in
FIG. 5
or
FIG. 6
, the diaphragm has a long durability. In case of a diaphragm shown in
FIG. 4
which is integrated with a driving portion, the diaphragm is attached to the driving plate by pressing a fitting portion formed on the driving member into a fitting hole formed in the driving plate. The diaphragm which is configured as described above poses a problem that portions of the fitting portion of the driving member and the driving plate (a portion of the fitting hole of the driving plate) which brought into contact with each other are abraded due to rubbing and the like.
However, the reciprocating pump according to the present invention which is configured as shown in
FIG. 5
or
FIG. 6
is completely free from the problems posed by the conventional example.
Each of the reciprocating pumps (miniature pumps) according to the first and second embodiments of the present invention is configured to dispose the spring under the driving body which performs the pump function by changing the volume of the pump chamber so that the driving member always presses the ball, thereby moving the ball at a nearly constant speed and being capable of performing a favorable pump function. Furthermore, the diaphragm has the nearly linear sectional shape and a prolonged service life.
FIG. 8
shows a pump according to a third embodiment, wherein a reference numeral
121
represents a driving motor, a reference numeral
122
designates an output shaft of the motor
121
, a reference numeral
123
denotes a bush which is fixed to the output shaft
122
, a reference numeral
125
represents a driving magnet which is fixed to a driving yoke
124
attached to the bush
123
by means such as caulking: these members being accommodated in a first case
130
. A reference numeral
140
represents a second case and a reference numeral
150
designates a third case (cylinder case), a sealed chamber
131
is formed by coupling these second and third cases airtightly by way of an O ring
126
, and the second case
140
is fixed to the first case
130
, whereby the first, second and third cases are combined so as to compose an outside frame of the pump. Formed at a central portion of the second case
140
in the sealed chamber
131
is a boss portion
140
b
to which a shaft
132
is pressed and fixed. A reference numeral
133
represents a rotating plate which is disposed rotatably around the shaft
132
, a reference numeral
134
designates a yoke and a reference numeral
135
denotes a follower magnet: these yoke
134
and follower magnet
135
being embedded in a magnet holding portion
133
a
of the rotating plate
133
and hold by fixing a holding plate
136
to the rotating plate
133
. The follower magnet
135
is configured to be disposed at a location opposed to the driving magnet
125
. A concave groove
133
b
which has a circumferential shape (ring shape) and an arc like section is formed along an outer circumferential surface of the rotating plate
133
, and ball drop preventing walls
133
c
are formed concentrically on both sides of (inside and outside) the concave groove
133
b
. A reference numeral
137
represents a ball which is disposed so as to be movable along the concave groove
133
b
which is formed in a top surface of the rotating plate
133
, and has the ring shape and the arc like section. In addition, a reference numeral
138
denotes a ball bearing which is disposed so that the rotating plate
133
rotates stably and smoothly.
Furthermore, a reference numeral
141
represents a piston portion (driving body) which has an upper portion configured as a piston (driving portion) performing a pump function and a lower portion having a ring like (circumferential) concave groove
141
b
which is formed along a circumference and has an arc like section. A bottom surface as a whole of the piston portion is an inclined surface having a constant gradient. That is, the ring like surface in which the concave groove
141
b
is formed as a cam surface which is lowest (closest to the rotating plate
133
) on a right side in FIG.
8
and highest (farthest from the rotating plate
133
) on a left side. In addition, formed in the piston portion
141
are flow paths
143
and
144
through which a fluid is to flow. The above described ball
137
is located between the concave groove
141
b
of the piston portion
141
and the concave groove
133
b
formed in the rotating plate
133
as shown in FIG.
8
. Accordingly, the piston portion
141
is moved up and down by the ball which moves along the concave grooves
133
b
and
141
b
when the rotating plate
133
is rotated.
Reference numerals
151
and
152
represent a suction valve and a discharge valve respectively, reference numerals
153
and
154
designate a suction port and a discharge port respectively formed in the third case, a reference numeral
155
denotes a pump chamber and a reference numeral
156
represents a spring.
In addition, the suction valve
151
is a ring having a circular opening at a center, a side which is fixed to the piston portion (driving portion) with a screw and the other side which opens and closes a flow path communicated with the suction port
153
. The piston (driving portion)
141
a
is fitted in the circular opening. Similarly, the discharge valve
152
is also a ring having a circular opening in which the spring
156
is located.
The third embodiment of the present invention is configured to rotate the ring like driving magnet
125
together with the driving yoke
124
when the output shaft
122
is driven and rotated by the motor
121
. When the driving magnet
125
is rotated, the ring like follower magnet
135
which is disposed in opposition to the driving magnet
125
with a bottom surface
140
a
of the second case
140
interposed is also rotated. When the follower magnet
135
is rotated, the rotating plate
133
is rotated, thereby moving the ball
137
. This movement of the ball
137
causes a change of a position (vertical position in
FIG. 8
) of the cam surface
141
a
which is in contact with the ball
137
, whereby the piston member
141
reciprocates along a straight line in a vertical direction in
FIG. 8
along the cylinder portion
157
. That is, the piston portion
141
makes nearly a reciprocal movement when the ball
137
moves about 360°. Since the piston portion (driving body)
141
is always pressed by the spring
156
, the concave groove
141
b
which is the cam surface of the piston portion
141
is in close contact with the ball
137
and the ball
137
is in close contact with the concave groove
133
b
of the rotating plate
133
. The ball
137
therefore turns (rotates) and moves (revolves) while being kept in close contact with the concave groove
133
b
and the concave groove
141
b
when the rotating plate
133
is rotated. Accordingly, the piston portion
141
moves up and down as described above.
FIG. 10
shows the movement of the piston portion which starts from a left side (position shown in
FIG. 8
) is positioned highest (position shown in
FIG. 9
) when the ball moves 180° and lowest when the ball further moves 180°, that is, when the ball moves from 0° to 360°. That is, the piston portion returns to the position shown in FIG.
8
.
In
FIG. 10
, a horizontal direction represents a movement amount of the ball expressed in terms of an angle and a vertical direction designates a movement of the piston portion corresponding to the movement of the ball.
During the reciprocal movement of the piston portion
141
, the piston portion
141
is lowered until the ball
137
moves 180° and is set in a condition shown in
FIG. 9
as described above, whereby a volume of the pump chamber
155
is increased, a pressure is lowered and the discharge valve
152
opens. On the other hand, a volume of the sealed chamber
131
in the second case
150
is decreased and a pressure is enhanced, whereby the suction valve
151
is closed. While the ball
137
further moves 180° and returns to a condition shown in
FIG. 8
, the piston portion
141
is gradually enhanced, the discharge valve
152
is closed, and a fluid in the pump chamber is discharged through the discharge port
154
and supplied to a desired location. Furthermore, a volume of the sealed chamber
131
is increased and the pressure is lowered. Accordingly, the suction valve
151
opens, and the fluid flows through the suction port
153
and fills the sealed chamber
131
, the flow paths
143
,
144
and the like.
When the piston portion
141
is further enhanced, the fluid flows out of the pump chamber
155
through the discharge port
154
. The pump function is performed by repeating these operations.
The pump according to the third embodiment is configured to rotate and revolve the ball, thereby moving about 180° along the concave grooves
133
b
and
141
b
while the rotating plate
133
makes a turn, and further move the ball about 180° or about 360° while the rotating plate further makes a turn, that is, two turns from start.
The piston portion makes advance or retreat of one turn around the cylinder as the ball moves about 180° and the piston portion makes retreat or advance as the ball moves about 360°.
The third embodiment of the present invention is configured to allow the piston member
141
to make about a reciprocal movement while the rotating plate
133
makes about two turns as described above. Since the cam surface (concave groove)
141
b
of the piston portion is inclined, the cam surface
141
b
is actually longer than the concave groove
133
b
of the rotating plate
133
and a length of the cam surface
141
b
is different dependently of an inclination angle. That is, the pump according to the third embodiment has a speed which is reduced from a rotating frequency of the rotating plate at a ratio of 1:2.2 to 1:2.3.
The miniature pump according to the third embodiment of the present invention is configured to move up and down (reciprocate) the driving body composed of the piston portion
141
by the movement of the ball
137
caused by the rotation of the rotating plate
133
owing to a function of the cam surface which is formed in a bottom surface of the driving body composed of the piston portion
141
and has the constant gradient, whereby the pump function is performed by the reciprocal movement of the piston portion (driving body)
141
a
of the piston portion (driving body)
141
as described above. Since the pump according to the third embodiment of the present invention is a pump which uses a piston as described above, the pump is capable of obtaining a sufficient pressure even when the pump is used as a liquid pump. Furthermore, the pump can be configured compact since a driving mechanism for driving the piston consists of a combination of the rotating plate, the cam surface and the ball.
Furthermore, since the driving mechanism consisting of the rotating plate, the cam surface and the ball reciprocates the piston in a condition where a speed of the driving mechanism is reduced from the rotation of the rotating plate as described above, the pump is capable of reducing a speed without using a special speed reduction mechanism such as a reduction gear and being driven with a miniature motor. The third embodiment is therefore preferable for configuring a pump more compact and reducing a cost.
Though the cam surface having the gradient is formed on the bottom surface of the driving body in the third embodiment, it is possible to obtain a miniature pump which performs quite a similar pump function by forming a cam surface having a gradient on a surface of the rotating plate on a side of the driving body without sloping the bottom surface of the driving body. That is, it is possible to configure the concave groove
133
b
of the rotating plate
133
so as to have a constant gradient without sloping the concave groove
141
b
of the piston member
141
.
FIG. 11
is a diagram showing a fourth embodiment of the present invention. Unlike the pump according to the third embodiment, a pump according to the fourth embodiment is configured to drive a rotating plate
133
directly with a motor
121
and the rotating plate
133
is fixed to an output shaft
122
of the motor
121
.
That is, a reference numeral
121
represents the motor, a reference numeral
122
designates the output shaft, a reference numeral
133
denotes the rotating plate, a reference numeral
137
represents a ball, a reference numeral
141
designates a piston portion (driving body) and a reference numeral
157
denotes a cylinder portion in FIG.
11
.
In the fourth embodiment, a piston (driving portion)
142
a
and a cam portion
142
b
are configured separately, and these portions are fixed and integrated with a screw or the like so as to compose a piston portion (driving body). Furthermore, a piston ring
146
made of a material having a high sliding property is embedded in the cylinder portion
157
so that airtightness is maintained between the cylinder portion
157
and the piston portion
141
and the piston portion
141
can reciprocate smoothly. Furthermore, a flow path
144
is formed in the piston portion
141
, a flow path
159
is similarly formed also in the cylinder portion
157
, and valves
151
and
152
are disposed in these flow paths respectively.
Furthermore, a reference numeral
160
represents a fourth case (cover body), a second case
140
is kept airtight using an O ring
161
and a pump chamber
162
is formed in the fourth case
160
. A discharge port
163
is formed in the fourth case
160
. In addition, a suction port (not shown) is formed in the second case
140
.
The pump according to the fourth embodiment drives the motor
121
to rotate the output shaft
122
, thereby directly rotate the rotating plate
133
and moving the ball
137
along a concave groove
133
b
formed in the rotating plate
133
. This movement of the ball causes upward and downward movements of the piston portion
141
as in the third embodiment. A pump function is performed by the upward and downward movements, that is, reciprocal movements of the piston portion
141
.
That is, the piston portion
141
is lowered when the ball
137
moves 180° from a condition shown in
FIG. 11
to an opposite side. When the piston portion
141
is lowered, a fluid flows into the pump from an inlet port through the flow path
144
, thereby opening the valve
151
.
When the ball
137
further moves 180° successively and returns to a position shown in
FIG. 11
, the piston portion
141
is raised, whereby the fluid passes through the flow path
159
, opens the valve
152
and flows out through the discharge port
163
.
The pump according to the fourth embodiment shown in
FIG. 11
has a structure which makes it relatively difficult to manufacture the case
140
. For manufacturing the case
140
easily, it is preferable to manufacture two parts corresponding to a part
140
a
and a part
140
b
which are obtained by dividing the case
140
along a plane indicated by a two-point chain line
140
c
shown in
FIG. 11
, and join these two parts into the integral case
140
.
FIGS. 12 and 13
show a fifth embodiment of the miniature pump according to the present invention. The fifth embodiment is an example wherein a diaphragm pump is used as a pump,
FIG. 12
is a sectional view and
FIG. 13
is a partial plan view showing a fourth case.
In
FIGS. 12 and 13
, a reference numeral
121
represents a motor which is attached to a second case
140
, a reference numeral
122
designates an output shaft of the motor
121
, a reference numeral
133
denotes a rotating plate having a concave groove
133
b
which has an arc like sectional shape and is formed in a ring like shape, reference numeral
137
represents a ball, a reference numeral
141
designates a driving body which has a concave groove
141
b
having a shape similar to that of the concave groove
133
b
formed in the rotating plate
133
and located so as to oppose to the concave groove
133
b
, and a driving portion
142
corresponding to the piston (driving portion) in the third embodiment. Furthermore, a surface which has the concave groove
141
b
of a bottom surface of the driving body
141
is configured as an inclined surface having a constant gradient which composes a cam surface. Furthermore, formed in this driving body
141
is a flow path
144
which is communicated with an inlet port (not shown) disposed in the case
140
and a valve
151
is attached to a tip portion of the flow path
144
. A reference numeral
170
represents a diaphragm which is attached to a tip portion of the driving portion
142
of the driving body
141
and a circumferential portion of this diaphragm which is the other end is sandwiched between cases
171
and
172
. A reference numeral
173
designates a ball serving as a detente and a steady rest which prevent the driving body
141
from being rotated relative to a second case and the like and allow the driving body
141
to move smoothly downward in FIG.
12
. This ball
173
is disposed, for example, at three locations as shown in
FIG. 13
, but the three locations are not limitative. Formed in the case
172
is a flow path
174
and a valve
152
is attached to a tip of the flow path
174
. Furthermore, a reference numeral
156
denotes a spring which is disposed between the driving body
141
and the case
171
for pressing the driving body
141
downward so that the driving body
141
is always in pressure contact with the ball
173
, and a reference numeral
160
designates a fourth case (cover body) which has a discharge port
163
and forms a pump chamber
162
.
The miniature pump according to the fifth embodiment drives the motor
121
to rotate the output shaft
122
, thereby rotating the rotating plate
133
. When the rotating plate
133
is rotated, the ball
137
rotates and revolves, thereby moving between the concave groove
133
b
of the rotating plate
133
and the concave groove
141
b
(groove in the cam surface) of the driving body
141
. When the ball
137
moves, the driving body
141
moves up and down, and the driving portion
142
also moves up and down, thereby increasing and decreasing a volume of the pump chamber composed of the diaphragm, and the like, and performing a pump function. That is, the volume of the pump chamber
175
is increased as the driving body is lowered, the valve
151
is opened and a fluid flows into the pump chamber
175
through the flow path
144
. Furthermore, when the volume of the pump chamber
175
is decreased, that is, when a pressure is enhanced as the driving body
141
is raised, the valve
151
is closed and the valve
152
is opened, whereby the fluid is discharged from the discharge port
163
disposed in the fourth case (cover body)
160
. The pump function is performed by repeating these operations.
The fifth embodiment uses the diaphragm and performs the pump function with the driving portion which reciprocates along a straight line, thereby being free from unnatural deformation of the diaphragm and preferable from a viewpoint of a durability.
The miniature pump according to the fourth and fifth embodiments described above are also configured to have gradients at portions of the concave grooves which are formed in the ring shapes as the cam surfaces in the vicinities of the bottom surfaces of the driving bodies (piston portions), that is, the surfaces on the sides of the rotating plates and perform the pump functions by moving up and down the driving bodies. However, it is possible to configure the bottom surface of the driving body as a horizontal surface and form a constant gradient the ring like portion in which is concave groove of the rotating plate is formed, whereby the driving body is moved up and down by up and down movements of the ball caused when the ball moves.
Furthermore, it is desirable to dispose a rotation stop mechanism (the ball or the like shown in
FIGS. 12 and 13
) in the pump according to the third embodiment or the fourth embodiment though such a mechanism is not shown in
FIG. 8
or
FIG. 11
showing the pump according to the third or fourth embodiment.
Each of the pumps according to the third through fifth embodiments of the present invention is configured to reciprocate the driving body having the driving portion such as a piston with a combination of the ball and the cam surface, whereby a speed of the pump can be slowed down without using a speed reduction mechanism and the pump can be operated with a small motor. Furthermore, the pump is capable of obtaining a pressure sufficient for use as a liquid pump when a piston is used as a driving member.
Claims
- 1. A miniature pump comprising: a pump chamber which is communicated with a suction port by way of a check valve and communicated with a discharge port by way of another check valve; a driving portion which performs a pump function by increasing and decreasing a volume of said pump chamber; a driving plate to which said driving portion is attached and which reciprocates said driving portion; a rotating plate which is fixed to an output shaft of a motor; a ball disposed at a location which is between said driving plate and said rotating plate, and apart from said output shaft; and means for applying a force to a surface of said driving plate on a side of said rotating plate for bringing said driving plate into close contact with said ball, wherein an inclined direction of said driving plate is continuously changed by a movement caused due to rotations and revolutions of said ball as said rotating plate rotates, thereby reciprocating said driving portion and performing a pump function.
- 2. The miniature pump according to claim 1, wherein said means for applying the force to said driving plate is a spring which is disposed between said driving plate and said rotating plate and in the vicinity of a rotating shaft.
- 3. The miniature pump according to claim 2, wherein said pump comprises a spring bearing which is disposed in the vicinity of said output shaft and kept fixed during rotations of said rotating plate, and said spring is disposed between said driving plate and said spring bearing.
- 4. The miniature pump according to claim 3, wherein said spring bearing is held by said output shaft by way of a ball bearing.
- 5. The miniature pump according to claim 1, wherein said means for applying the force to said driving means is a plurality of springs which are located around said driving plate and outside an outer circumference of said rotating plate.
- 6. A miniature pump comprising: a pump chamber which is communicated with a suction port by way of a check valve and communicated with a discharge port by way of another check valve; a driving portion which performs a pump function by increasing and decreasing a volume of said pump; a driving plate which reciprocates said driving portion; a rotating plate which is fixed to an output shaft of a motor; and a ball which is disposed between said driving plate and said rotating plate, wherein a cam surface is formed on said driving plate on a side of said rotating plate, and rotations of said rotating plate causes rotations and revolutions of said ball so as to cause a movement of the ball, which produces a function of the cam surface for reciprocating said driving portion together with said driving plate, thereby performing a pump function.
- 7. The miniature pump according to claim 6, wherein said pump comprises a cylinder which composes said pump chamber and a piston which composes said driving member.
- 8. The miniature pump according to claim 6, wherein said pump comprises a diaphragm which composes said pump chamber and said driving portion is integrated with said diaphragm.
- 9. The miniature pump according to claim 6, 7 or 8, wherein said pump comprises a driving magnet which is fixed to said output shaft, and a follower magnet which is disposed in opposition to said driving magnet and fixed to said rotating plate, and wherein said motor drives the output shaft so as to rotate the driving magnet and the rotations of said driving magnet causes rotations of said follower magnet due to magnetic coupling, thereby rotating said rotating plate and performing a pump function.
Priority Claims (2)
Number |
Date |
Country |
Kind |
2000-326645 |
Oct 2000 |
JP |
|
2000-355803 |
Nov 2000 |
JP |
|
US Referenced Citations (5)
Foreign Referenced Citations (2)
Number |
Date |
Country |
62291484 |
Dec 1987 |
JP |
11230046 |
Aug 1999 |
JP |